A method of providing video on demand to a set-top box includes sending playing parameters of a video file to a video on demand server, and receiving information of the video file and predetermined quality of service parameters of the set-top box. The method further includes receiving updated quality of service parameters input by a user, and sending the updated quality of service parameters to a worldwide interoperability for microwave access client module of the set-top box, and sending the updated quality of service parameters to a worldwide interoperability for microwave access base station. The method also includes sending a playback instruction to the video on demand server, and receiving video streaming data of the video file based on the updated quality of service parameters from the video on demand server.